In the past, as an image forming apparatus, there are known apparatuses, e.g., MFPs (Multi-Function Peripherals), having a plurality of functions such as printing functions for printing images on sheets and reading functions for reading documents by using scanners.
The image forming apparatus includes a printer device for the printing function, a scanner device for the reading function, and the like. The printer device, the scanner device, and the like are stored in a main casing.
Further, the image forming apparatus includes a feeder unit that supplies sheets to the printer device. Examples of the feeder unit includes a regular feeder unit that supplies sheets stored in the paper cassette to the printer device, and a large-volume feeder unit capable of storing sheets more than the sheets stored in the regular feeder unit. The regular feeder unit and the large-volume feeder unit are stored in the dedicated casings independent of the main casing.
Depending on the type of usage, the dedicated casing of the feeder unit is connected to the main casing, and the feeder unit functions as a feeder of the image forming apparatus.
For example, the dedicated casing of the regular feeder unit is connected to the lower portion of the main casing. Further, the dedicated casing of the large-volume feeder unit is connected to the dedicated casing of the regular feeder unit of the lower portion.
Alternatively, in place of the dedicated casing of the regular feeder unit, the dedicated casing of the large-volume feeder unit is connected to the lower portion of the main casing.
Further, examples of the image forming apparatus having the plurality of functions include an apparatus having an erasing function. According to the erasing function, the apparatus heats an image printed on a sheet with an erasable toner or the like at a predetermined erasing temperature, for example, and thereby erases the image in order to reuse the sheet on which the image is printed.
The image forming apparatus having the erasing function includes an erasing unit for realizing the erasing function.
The erasing unit is also stored in a dedicated casing independent of the main casing.
The erasing unit is not capable of supplying an erased sheet to the printer device individually.
Because of this, even if the dedicated casing of the erasing unit is connected to the main casing of the image forming apparatus in place of the dedicated casing of the feeder unit, the erasing unit is not capable of supplying the sheet to the printer device.
So, according to a conventional image forming apparatus, even if the erasing unit is used, it is not possible to diversify means for supplying sheets to the printer device.
According to a conventional image forming apparatus, the dedicated casing of the erasing unit is connected to, for example, the lower portion of the dedicated casing of the feeder unit in order that the erasing unit may supply erased sheets to the feeder unit.
According to an another idea, the feeder unit including the paper cassettes and the like and the erasing unit may be embedded in one dedicated casing to thereby integrate the feeder unit and the erasing unit. However, if both the units are integrated, it is necessary to consider how to maintain the units when setting sheets in the paper cassette, when clearing a paper jam of the erasing unit, and the like.